IBM AS400 Interview Questions Answers: Series II

What is Spool file, Why is it required?
Ans:A file that holds output data to be processed, such as information waiting to be printed.

What is Job, What are the attributes of a Job?
Ans:A Job is a basic unit of work on AS/400.
The attributes are:
Job Number Unique system generated sequential number
Job Name Any user defined name (Max 10 char)
User Name Who initiated the job.

What is Job description?
Ans:A Job description defines an environment in which a batch job or an interactive job to be executed.

What is the difference between Interactive & Batch Job?
Ans:
Interactive Job: A Job started for a person who signon to a workstation.
Batch Job : A predefined group of processing actions submitted to the system to be performed.
What is Group Job?

Ans:A Group Job is attached to one workstation and a user. There should be an initial group job and it can be branched to many other group jobs. The group jobs can have different library lists and different output, message queues. Group Job is useful in enhancing the programmers productivity. It is as though logging into the same user-id many times.

What are the two main attributes, which govern the execution of a job?
Ans:Run time priority and Time slice

What is Sub-System?
Ans:Sub-Systems are specific user defined partitions of the CPU where various jobs may be executed. One subsystem can have more than one active job at a time.

What is a Device file?
Ans:A device file contains the description of how data is to be presented to a program from a device or vice versa. Device file can be Printer, Disk, Tape and Remote system.

What is the maximum number of key fields allowed defining in a physical file?
Ans:120

What is acronym of RPG?
Ans:Report Program Generator

What is the native language of AS/400?
Ans:RPG/400

Why RPG/400 is famous?
Ans:* Easy to code and analyze.
* Supports externally described files.

What is an ICF file?
Ans:A device file that allows a program on the system to communicate with program in other system.

What is a message file?
Ans:It is a file which contains the messages of an application. For example all RPG/400 messages are stored in a file, all COBOL/400 messages are stored in a file.

What is a job log?
Ans:A record of request submitted to system be a job. The message related to the requests, and action performed by the system on the log. The system program maintains it.

What is the purpose of OPNQRYF (Open Query File)?
Ans:OPNQRYF is used to select certain records of the database file based on the QRYSLT (Query select ) condition.

How to create files dynamically without DDS?
Ans:Through OPNQRYF

What command must be executed before executing OPNQRYF command?
Ans:OVRDBF (Override Data base file)

What is Data Area?
Ans:Data area is an object used to hold data for access by any job running on the system. A data area can be locked to a single user, thus preventing other users from processing at the same time.

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